The invention provides a process for forming crack-free dielectric films on a substrate. The process comprises the application of a dielectric precursor layer of a thickness from about 0.3 μm to about 1.0 μm to a substrate. The deposition is followed by low temperature heat pretreatment, prepyrolysis, pyrolysis and crystallization step for each layer. The deposition, heat pretreatment, prepyrolysis, pyrolysis and crystallization are repeated until the dielectric film forms an overall thickness of from about 1.5 μm to about 20.0 μm and providing a final crystallization treatment to form a thick dielectric film. The process provides a thick crack-free dielectric film on a substrate, the dielectric forming a dense thick crack-free dielectric having an overall dielectric thickness of from about 1.5 μm to about 20.0 μm.
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1. A process for forming a crack-free barium strontium titanate (BST) dielectric comprising: providing a substrate; depositing a first dielectric precursor BST sol-gel layer having a thickness from about 0.3 μm to about 1.0 μm on a substrate; heating the first dielectric precursor BST sol-gel layer at a preheat temperature from about 100° C. to about 200° C. for a preheat temperature heating time from about 1 minute to about 30 minutes; initiating a step-wise preheat treatment using three distinct temperatures comprising increasing the temperature from about 275° C. to about 325° C. in a pre-pyrolysis step and maintaining the temperature at the pre-pyrolysis temperature for a pre-pyrolysis period of time; increasing the temperature from about 375° C. to about 425° C. in a first pyrolysis step and maintaining the temperature at the first pyrolysis temperature for a first pyrolysis period of time; increasing the temperature from about 425° C. to about 475° C. in a second pyrolysis step and maintaining the temperature at the second pyrolysis temperature for a second pyrolysis period of time; initiating a crystallization treatment comprising increasing the temperature from about 600° C. to about 800° C. for a period of time to crystallize at least one layer; wherein all heat treatments were performed in an ambient atmosphere and wherein temperature changes are achieved by moving the film into different zones; and repeating the deposition step, initial heating step, pyrolyzing and crystallization steps to form a BST layer having a total thickness from about 1.5 μm to about 20.0 μm on a substrate to form a crystallized dielectric.
A method for creating a crack-free barium strontium titanate (BST) dielectric film involves depositing a BST sol-gel layer (0.3-1.0 μm thick) onto a substrate. This layer undergoes a preheating step at 100-200°C for 1-30 minutes. Next, a three-stage pre-pyrolysis/pyrolysis process is applied, increasing temperature through 275-325°C, 375-425°C, and finally 425-475°C, maintaining each temperature for a set duration. A crystallization step then heats the film to 600-800°C to crystallize at least one layer. All heating occurs in ambient atmosphere by moving the film between temperature zones. The deposition, preheating, pyrolysis, and crystallization steps are repeated to build up a BST layer with a total thickness of 1.5-20.0 μm, resulting in a crystallized crack-free dielectric.
2. The process of claim 1 , further comprising heating the substrate and BST layer to crystallize the BST at a temperature from about 600° C. to about 800° C. for a final crystallization time to form crystallized BST.
The crack-free barium strontium titanate (BST) dielectric film process, which involves depositing a BST sol-gel layer (0.3-1.0 μm thick) onto a substrate, preheating at 100-200°C for 1-30 minutes, a three-stage pre-pyrolysis/pyrolysis process increasing temperature through 275-325°C, 375-425°C, and 425-475°C, and crystallizing at 600-800°C, further includes a final crystallization step. This final step heats the substrate and BST layer to a temperature between 600°C and 800°C for a final crystallization time. This final heating ensures complete crystallization of the BST, improving its dielectric properties and crack resistance.
3. The process of claim 1 wherein the pre-heating time is from about 2 minutes to about 10 minutes.
The crack-free barium strontium titanate (BST) dielectric film process, which involves depositing a BST sol-gel layer (0.3-1.0 μm thick) onto a substrate, initiating a step-wise preheat treatment using three distinct temperatures comprising increasing the temperature from about 275° C. to about 325° C. in a pre-pyrolysis step and maintaining the temperature at the pre-pyrolysis temperature for a pre-pyrolysis period of time; increasing the temperature from about 375° C. to about 425° C. in a first pyrolysis step and maintaining the temperature at the first pyrolysis temperature for a first pyrolysis period of time; increasing the temperature from about 425° C. to about 475° C. in a second pyrolysis step and maintaining the temperature at the second pyrolysis temperature for a second pyrolysis period of time; initiating a crystallization treatment comprising increasing the temperature from about 600° C. to about 800° C. for a period of time to crystallize at least one layer; wherein all heat treatments were performed in an ambient atmosphere and wherein temperature changes are achieved by moving the film into different zones; and repeating the deposition step, initial heating step, pyrolyzing and crystallization steps to form a BST layer having a total thickness from about 1.5 μm to about 20.0 μm on a substrate to form a crystallized dielectric, specifies the initial pre-heating time to be between 2 minutes and 10 minutes.
4. The process of claim 1 , wherein the first dielectric precursor is a barium strontium titanate (BST) soluble gel solution containing polyvinylpyrrolidone.
In the process for creating a crack-free barium strontium titanate (BST) dielectric film – which involves depositing a BST sol-gel layer (0.3-1.0 μm thick) onto a substrate, preheating at 100-200°C for 1-30 minutes, a three-stage pre-pyrolysis/pyrolysis process increasing temperature through 275-325°C, 375-425°C, and 425-475°C, and crystallizing at 600-800°C – the first dielectric precursor is a barium strontium titanate (BST) soluble gel solution that also contains polyvinylpyrrolidone. The addition of polyvinylpyrrolidone to the BST sol-gel helps to improve the film's properties and crack resistance.
5. The process of claim 1 wherein the deposition step, initial heating step, pyrolyzing and crystallization steps are repeated to form a dielectric precursor layer having a thickness from about 2.0 μm to about 5.0 μm on the substrate.
The crack-free barium strontium titanate (BST) dielectric film process, which involves depositing a BST sol-gel layer (0.3-1.0 μm thick) onto a substrate, preheating at 100-200°C for 1-30 minutes, a three-stage pre-pyrolysis/pyrolysis process increasing temperature through 275-325°C, 375-425°C, and 425-475°C, and crystallizing at 600-800°C, involves repeating the deposition, heating, pyrolyzing, and crystallization steps until the dielectric precursor layer reaches a thickness between 2.0 μm and 5.0 μm on the substrate. This repetition builds up the desired thickness of the crack-free dielectric film.
6. The process of claim 1 wherein the final crystallization time is from about 10 to about 40 minutes.
In the process for creating a crack-free barium strontium titanate (BST) dielectric film – which involves depositing a BST sol-gel layer (0.3-1.0 μm thick) onto a substrate, preheating at 100-200°C for 1-30 minutes, a three-stage pre-pyrolysis/pyrolysis process increasing temperature through 275-325°C, 375-425°C, and 425-475°C, and crystallizing at 600-800°C – the final crystallization time, during which the substrate and BST layer are heated to crystallize the BST at 600-800°C, ranges from 10 to 40 minutes. This final crystallization time optimizes the crystallization process, enhancing the properties of the BST film.
7. The process of claim 1 wherein said substrate comprises a base metal.
In the process for creating a crack-free barium strontium titanate (BST) dielectric film – which involves depositing a BST sol-gel layer (0.3-1.0 μm thick) onto a substrate, preheating at 100-200°C for 1-30 minutes, a three-stage pre-pyrolysis/pyrolysis process increasing temperature through 275-325°C, 375-425°C, and 425-475°C, and crystallizing at 600-800°C – the substrate comprises a base metal.
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May 26, 2016
December 5, 2017
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